Shift Register Pre-Charging Circuit to Eliminate Signal Drift

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Solution Overview

Problem

Existing shift registers in display devices experience a drifting phenomenon due to floating nodes interfering with each other, leading to unstable output signals and reduced reliability.

Innovation Solution

A shift register design incorporating a pre-charging circuit, pulling-up circuits, and a reverse circuit to manage clock signals and voltages, preventing node interference and stabilizing output signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a conventional shift register structure with floating nodes is used to reduce device complexity, then the circuit design is simpler, but signal drift occurs due to node interference leading to reduced reliability

Engineering Contradiction:
Improvecircuit structureVSAvoidoutput signal stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent extracts and removes the problematic floating node from the circuit by replacing it with a dedicated pre-charging circuit that actively maintains node B at a stable high potential. This eliminates the source of interference while preserving the overall shift register functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The pre-charging circuit performs preliminary action by proactively charging node B to a high potential level before the interference issue can manifest. This preventive measure ensures that node B remains stable and does not float, thereby preventing signal drift before it occurs.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If more switching elements are integrated into limited space to meet display requirements, then display functionality is improved, but processing steps and manufacture cost increase

Engineering Contradiction:
Improvedisplay functionalityVSAvoidprocessing steps and cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The pre-charging circuit is designed to serve multiple functions: it charges node B to high potential, maintains it stable during operation, and prevents floating. This multi-functionality allows the circuit to achieve improved display functionality without proportionally increasing manufacturing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the pre-charging function with the existing shift register structure, integrating the new functionality into the available circuit space rather than adding completely separate components. This approach enables enhanced functionality while minimizing increases in processing steps.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If floating nodes are allowed in the circuit to simplify design, then device complexity is reduced, but node interference causes signal drift and operational unreliability

Engineering Contradiction:
Improvecircuit designVSAvoidnode interference and signal drift
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potential harm of floating nodes into a benefit by using the pre-charging circuit to actively establish and maintain a defined high potential at node B. This transforms what would be an uncontrolled floating state into a controlled, stable state that enhances circuit reliability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The pre-charging circuit acts as an intermediary between the power supply and node B, mediating the potential level at node B to ensure it remains stable and does not float. This intermediary component isolates node B from interference while maintaining the simplified circuit design.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2966649B1Shift register, gate electrode driver circuit, array substrate, and display device
Publication Date: 2024.01.03 BOE TECHNOLOGY GROUP CO LTD
  • EP2966649B1 patent drawingFigure 1
  • EP2966649B1 patent drawingFigure 2~3
  • EP2966649B1 patent drawingFigure 4

AI summary

Embodiments of the present disclosure disclose a shift register, a gate driving circuit, an array substrate and a display apparatus capable of effectively eliminating a drifting phenomenon of an output signal and increasing an output stability of the shift register. The shift register comprises input terminals of the shift register comprising a start signal input terminal, a first clock signal input terminal and a second clock signal input terminal; a pre-charging circuit which is in response to a start signal and a first clock signal; a first pulling-up circuit which is in response to an enable level of the start signal and an enable level of the first clock signal; a pulling-down circuit which is in response to a disable level of the first clock signal and an enable level of the second clock signal; a second pulling-up circuit; and an output terminal of the shift register.